1. Field of the Invention
The present invention relates to a reel on which is wound a recording tape, such as a magnetic tape or the like, used for storing data of a computer or the like.
2. Description of the Related Art
Conventionally, among recording tape cartridges used as recording media utilized in external storage devices of computers and the like, there is a type in which a single reel, on which a recording tape such as a magnetic tape or the like is wound, is rotatably accommodated within a recording tape cartridge. The magnetic tape is used for storing data of a computer or the like, and important information is recorded thereon. Thus, the recording tape cartridge is structured such that the magnetic tape cannot be inadvertently pulled out therefrom when the recording tape cartridge is not being used (such as when the recording tape cartridge is being stored or the like), and also, so that trouble such as jamming of the tape or the like will not occur.
Recently, the storage capacity of recording tape cartridges has increased such that the amount of data which can be recorded has increased from several tens of gigabytes (GB) to several hundred GB. In order to realize such an increase in storage capacity, the track pitch width has been decreased, or the thickness of the magnetic tape has been decreased. However, high dimensional accuracy is therefore required of the recording tape cartridge itself as well. In particular, the dimensions and the configuration of the reel on which the magnetic tape is wound must be highly accurate.
However, at a reel, both the cylindrical hub on which the magnetic tape is wound, and the upper and lower flanges which are provided at the upper and lower end portions of the hub and which hold the transverse direction end portions of the magnetic tape wound around the hub, are molded of a resin material. Thus, there are cases in which slight deformation occurs due to changes in temperature and/or humidity at the time when the recording tape cartridge is being transported. When such deformation arises at the hub in particular, a problem arises in that a fair amount of the magnetic tape is adversely affected thereby, i.e., bending due to this deformation of the hub arises at the magnetic tape itself.
In order to improve the dimensional accuracy of the reel, there has been the proposal to fit a ring-shaped member formed of metal on the outer side of the hub which is formed of resin. However, when the temperature becomes high, time is required for the temperature at the outer surface (the outer peripheral surface) of the ring-shaped member to drop, and there is the concern that the magnetic tape may be adversely affected by the temperature.